Jack foot retraction system

ABSTRACT

A system for supporting a vehicle. The system may include a vehicle jack in mechanical communication with a jack foot and a striker plate. The jack foot is rotatable relative to the vehicle jack on a rotation axis disposed on the vehicle jack and perpendicular to a long axis of the vehicle jack. The jack foot includes a base at a distal end of the jack foot. The jack foot also includes a cam surface at least in part at a proximal end of the jack foot. The cam surface is aligned with the striker plate and interacts with the striker plate to rotate the jack foot in response to movement of the vehicle jack from a lowered position to a raised position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/241,897, filed Sep. 12, 2009, which is herebyincorporated by reference herein in its entirety, including but notlimited to those portions that specifically appear hereinafter, theincorporation by reference being made with the following exception: Inthe event that any portion of the above-referenced application isinconsistent with this application, this application supercedes theabove-referenced application.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

1. The Field of the Present Disclosure

The present disclosure relates generally to jacks, and moreparticularly, but not necessarily entirely, to a trailer tongue jackfoot that is capable of retracting.

2. Description of Related Art

When a trailer is parked and detached from a tow vehicle, a support isrequired for the trailer tongue. Although other objects might be used,generally a special purpose jack (called a trailer jack or tongue jack)attached to the tongue is used. In addition, various types of vehicles,such as trailers and recreational vehicles (Rvs) use vehicle jacks forleveling the vehicle. Vehicle jacks generally are mounted vertically, orare pivotable to a vertical position, and have a telescoping portion (orinner tube) and a crank for upwardly and downwardly moving thetelescoping portion. Such jacks provide static support, leveling, andfacilitate detaching the tongue from the trailer hitch on the towvehicle by allowing the tongue to be raised relative to the hitch,thereby disengaging the tongue from the hitch.

Devices for supporting trailer tongues are well known. U.S. Pat. No.2,159,395 for “Trailer Control,” describes a pivotable wheel assemblywhich may be cranked to a down position whereby the trailer tongue issupported. U.S. Pat. No. 2,638,315 for “Trailer Attached Jack,”describes a simple telescoping jack for supporting a trailer tongue.U.S. Pat. No. 2,638,315 for “Trailer Attached Jack,” describes atelescoping tongue jack similar to modern jacks. The jack of the '315patent includes a crank for turning a screw shaft, which screw shaft isheld in place by a thrust bearing, and cooperates with a nut attached toan inner telescoping tube to extend or retract the inner tube. U.S. Pat.No. 3,314,693 for “Retractable Trailer Tongue Jack,” describes a jackhaving a screw shaft with a ring gear. A crank turns a pinion gearengaging the ring gear to turn the screw shaft, thereby extending orretracting an inner tube. U.S. Pat. No. 5,435,523 for “Trailer TongueJack,” describes a tongue jack with a pair of cooperating beveled gearscoupling a crank to a screw shaft.

One major disadvantage of the present tongue jacks is the time andeffort required to fully raise and lower the tongue jack in order tohook up or unhook the trailer. For example, at times the jack is notlong enough to reach the ground and lift the trailer to a sufficientheight to enable the operator to hook up or unhook the trailer. Oftentimes, the operator will employ “spacers” (e.g. blocks of wood, cinderblocks, etc.) to allow the jack to raise the trailer higher and/or toreduce the travel of the jack and thereby reduce the time and energyrequired to crank the jack all the up and down. In some cases, theoperator may not fully retract the inner tube due to time constraints orapathy. However, towing a trailer with a jack that is not fullyretracted may result in damage to the jack and trailer because the jackmay hit the ground during transportation. In order to avoid thisundesirable possibility, the operator is required to fully extend andretract the jack each time the operator hooks up or unhooks the trailer.

The features and advantages of the present disclosure will be set forthin the description which follows, and in part will be apparent from thedescription, or may be learned by the practice of the present disclosurewithout undue experimentation. The features and advantages of thepresent disclosure may be realized and obtained by means of theinstruments and combinations particularly pointed out in thisdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the disclosure will become apparent froma consideration of the subsequent detailed description presented inconnection with the accompanying drawings in which:

FIG. 1 depicts a typical trailer attached to a tow vehicle;

FIG. 2 shows the trailer of FIG. 1 including a trailer tongue jack;

FIG. 2 a shows a trailer including corner jacks;

FIG. 2 b shows a fifth-wheel trailer including corner jacks;

FIG. 2 c shows a recreational vehicle with corner jacks;

FIG. 3 illustrates one embodiment of a vehicle jack;

FIG. 4 illustrates another embodiment of a vehicle jack;

FIG. 5 is perspective view of one jack foot embodiment according to thepresent disclosure;

FIG. 6 is a front view of the jack foot of FIG. 5;

FIG. 7 is a rear view of the jack foot of FIG. 5;

FIG. 8 is a side view of the jack foot of FIG. 5;

FIG. 8 a is a side view of the jack foot of FIG. 5 and illustratesaspects of the jack foot relating to physical properties of the jackfoot;

FIG. 8 b is a side view of the jack foot of FIG. 5 and illustratesgeometric properties of the jack foot;

FIG. 8 c is a side view of the jack foot of FIG. 5 and illustrates thecam surface;

FIG. 8 d is a side view of one jack foot embodiment illustrating the camsurface;

FIG. 9 illustrates the retracting motion of the jack foot of FIG. 5;

FIG. 10 illustrates the fully retracted position of the jack foot ofFIG. 5;

FIG. 11 shows the extending motion of the jack foot of FIG. 5;

FIG. 12 depicts the fully extended and locked position of the jack footof FIG. 5.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles inaccordance with the disclosure, reference will now be made to theembodiments illustrated in the drawings and specific language will beused to describe the same. It will nevertheless be understood that nolimitation of the scope of the disclosure is thereby intended. Anyalterations and further modifications of the inventive featuresillustrated herein, and any additional applications of the principles ofthe disclosure as illustrated herein, which would normally occur to oneskilled in the relevant art and having possession of this disclosure,are to be considered within the scope of the disclosure claimed.

Before the present apparatus and methods for reducing the time andeffort required to hook up and unhook trailers are disclosed anddescribed, it is to be understood that this disclosure is not limited tothe particular configurations, process steps, and materials disclosedherein as such configurations, process steps, and materials may varysomewhat. It is also to be understood that the terminology employedherein is used for the purpose of describing particular embodiments onlyand is not intended to be limiting.

The publications and other reference materials referred to herein todescribe the background of the disclosure, and to provide additionaldetail regarding its practice, are hereby incorporated by referenceherein in their entireties, with the following exception: In the eventthat any portion of said reference materials is inconsistent with thisapplication, this application supercedes said reference materials. Thereference materials discussed herein are provided solely for theirdisclosure prior to the filing date of the present application. Nothingherein is to be construed as a suggestion or admission that theinventors are not entitled to antedate such disclosure by virtue ofprior disclosure, or to distinguish the present disclosure from thesubject matter disclosed in the reference materials.

It must be noted that, as used in this specification, the singular forms“a,” “an,” and “the” include plural referents unless the context clearlydictates otherwise.

In describing and claiming the present disclosure, the followingterminology will be used in accordance with the definitions set outbelow.

As used herein, the terms “comprising,” “including,” “containing,”“characterized by,” and grammatical equivalents thereof are inclusive oropen-ended terms that do not exclude additional, unrecited elements ormethod steps.

As used herein, the term “proximal” shall refer broadly to the conceptof a nearest portion.

As used herein, the term “distal” shall generally refer to the oppositeof proximal, and thus to the concept of a further portion, or a furthestportion, depending upon the context.

As used herein, the phrase “in an at least partially proximal-to-distaldirection” shall refer generally to a two-dimensional concept ofdirection in which the “proximal-to-distal” direction defines onedirection or dimension. An item that extends in anon-parallel directionwith respect to the “proximal-to-distal” direction, that is, at anon-straight angle thereto, thereby involves two components ofdirection, one of which is in the “proximal-to-distal” direction and theother being in a direction orthogonal to the “proximal-to-distal”direction.

The prior art is characterized by several disadvantages that areaddressed by the present disclosure. The present disclosure minimizes,and in some aspects eliminates the above-mentioned problems by utilizingthe methods and structural features described herein. For example,embodiments of the jack foot retraction system disclosed herein addressthe problems of the prior art by giving additional blocking to thebottom of the jack to reduce the cranking travel needed each time thejack is used, as well as eliminating the need to store commercialdetachable jack feet, wood, cinder blocks, etc. Additionally,embodiments of the jack foot retraction system stay attached to thetrailer tongue jack and fold out of the way to provide ground clearanceduring transportation.

Applicant has discovered that trailer hook up and unhook procedures aregreatly enhanced by utilizing a device to reduce the time and effortrequired to hook up and unhook trailers from a tow vehicles. Applicanthas thus conceived of an extendable/retractable jack foot device that iscapable of providing stable support for a trailer while in the extendedconfiguration and then folding up to provide better ground clearance inthe retracted configuration to enable the trailer to be safely towed,while simultaneously reducing the time and effort required to hook upand unhook trailers from the tow vehicle.

Referring now to FIG. 1, a trailer 10 is shown connected to a towvehicle 12 with trailer tongue 14 connected to trailer hitch 16 of thetow vehicle 12. The tongue 14 and hitch 16 combine to provide aconnection for pulling the trailer 10, and vertical support for thetongue 14. The total weight transferred from the tongue 14 to the hitch16 is called “tongue weight,” and heavy trailers often have significanttongue weight. The trailer 10 is shown detached from the tow vehicle 14in FIG. 2. A trailer tongue jack 17 is used to support the tongueweight. On some trailers 10, the trailer 10 includes one or more cornerjacks 92. Corner jacks 92 are an additional form of vehicle jack thatmay be used to level or support the trailer 10. Collectively, trailertongue jacks 17 and corner jacks 92 are referred to herein as vehiclejacks. A trailer 10 may have two corner jacks 92 at either rear cornerof the trailer 10 that may work in conjunction with the trailer tonguejack 17 to level the trailer 10.

FIG. 2 a illustrates a trailer 10 having corner jacks 92 at each of thefour corners of the trailer 10. The trailer 10 may be leveled by use ofthe four corner jacks 92. Similarly, FIG. 2 b illustrates a fifth-wheeltrailer 94 that includes four corner jacks 92. The corner jacks 92 maybe used to level the fifth-wheel trailer 94. In addition, the two frontcorner jacks 92 may be used in hitching and un-hitching the fifth-wheeltrailer 94 from a tow vehicle 12. FIG. 2 c illustrates a recreationalvehicle (RV) 96 with corner jacks 92. The RV 96 may include a cornerjack 92 near each of the four corners of the RV 96 for leveling the RV96.

Two common types of vehicle jacks are shown in FIGS. 3 and 4. A firstvehicle jack 18 a with a first crank 26 a attached to a top end of thefirst vehicle jack 18 a is shown in FIG. 3. The first vehicle jack 18 aincludes a first outer tube 20 a, a first inner tube 22 a (also referredto herein as a moveable jack member), and a first crank 26 a. The firstouter tube 20 a includes a flange 24 for mounting the first vehicle jack18 a to the tongue 14, and the first crank 26 a includes a handle 28. Asecond vehicle jack 18 b with a second crank 26 b attached to a side ofthe second vehicle jack 18 b near the top of the second outer tube 20 bis shown in FIG. 4.

The two common types of vehicle jacks 18 a and 18 b, as shown in FIGS. 3and 4, typically have a small, simple base (not shown) attached to thedistal ends of the inner tubes 22 a and 22 b which contacts the groundand helps stabilize and support the trailer. Other types of vehiclejacks are also common. For example, vehicle jacks include electricallyactuated screw jacks that include an electric motor and hydraulic jacks.As used herein, vehicle jack refers to any type of vehicle jack,including crank jacks, electric jacks, hydraulic jacks, trailer tonguejacks, and corner jacks.

FIG. 5 shows one embodiment of a retractable/extendable jack foot 30 inaccordance with the present disclosure. The jack foot 30 can be attachedto a distal end of a telescoping inner tube 22 (similar to 22 a and 22 bin FIGS. 3 and 4) of a vehicle jack 18. It is to be understood that jackfoot 30 may be used with any number of jacks and jack types that are notspecifically shown in the present disclosure, including, but not limitedto crank jacks, electric jacks, hydraulic jacks, trailer tongue jacks,corner jacks, jacks for installation on trailer tongues, trailercorners, RV corners, fifth wheel trailers, or other vehicles. The jackfoot 30 supports the vehicle jack 18 in response to the jack foot 30being in a lowered position, the vehicle jack 18 being extended, and thejack foot 30 being loaded.

The jack foot 30, in some embodiments, can be attached to the inner tube22 by inserting the inner tube 22 into the jack foot 30, aligning theshaft hole 32 in the inner tube 22 with a shaft slot 34, which may alsobe referred to as a shaft slot window 34, and inserting a shaft (notshown) through the shaft slot window 34 into the shaft hole 32 to securethe jack foot 30 to the inner tube 22. In some embodiments, the shafthole 32 extends all the way through the inner tube 22 and there is aanother shaft slot window on a second lateral side of jack foot 30 (notshown), similar to the shaft slot window 34 on a lateral side 44 of thejack foot 30, such that the shaft can extend all the way through thejack foot 30 and the inner tube 22 and be secured on the second lateralside of the jack foot 30 with a fastener (not shown), such as a nut, apin, a rivet, or other securing device. The lateral side 44 may also bedescribed as a lateral side wall.

The shaft slot window 34 may have a substantially straight proximalsection terminating in a proximal end 34 a, and a substantially straightdistal section terminating in a distal end 34 b, the proximal sectionand the distal section intersecting at intersection 34 c and forming anangle θ as shown in FIG. 5, which could be an obtuse angle, such as 135degrees or any suitable angle within a range of 95 degrees to 175degrees, and said shaft slot window 34 is therefore non-linear. Theshaft slot window 34 resides in the upper proximal third of a jack footbody of the jack foot 30, as shown in FIG. 5 and elsewhere in thedrawings.

In one embodiment, the jack foot 30 can also have a pilot hole 52 tohelp facilitate proper alignment and attachment of the jack foot 30 tothe inner tube 22 by measuring the proper distance between the restingplate 46 and the center of the shaft hole 32 and allowing the operatorto drill a pilot hole at the proper distance. The pilot hole 52, in oneembodiment, is positioned a pre-determined distance from the front side42 of the jack foot 30. The front side 42 may also be described as afront side wall, such that the front side 42 resides between andintercouples the two opposing lateral side walls 44 to thereby form athree-sided jack foot body having a distal end 45 connected to the base54, as shown most clearly in FIG. 6, the three-sided jack foot bodythereby having three sidewalls and an open side as shown most clearly inFIGS. 5 and 7. As also shown most clearly in FIG. 6, the base 54 iswider in all directions than, and thereby surrounds the perimeter of,the distal end 45 of the jack foot body. The pre-determined distance maycorrespond to the distance between the resting plate 36 and the properposition for the center of the shaft hole 32. The proper position fordrilling the shaft hole 32 can be determined by positioning the jackfoot 30 over the end of inner tube 22 such that the distal end of theinner tube 22 contacts the front side 42 of the jack foot 30, anddrilling pilot holes in the inner tube 22, then removing the jack foot30 and drilling the pilot holes to the correct diameter for the shafthole 32 to receive a shaft (not shown).

Referring now to FIGS. 7-8, it is to be understood that the sidewall 44shown in FIG. 8 can be identical to its opposing sidewall 44 (not shownin FIG. 8), such that shaft 64 is disposed within and extends betweenthe first shaft slot window 34 and an opposing second shaft slot window(not shown in FIG. 8 but which is in the opposing lateral sidewall inmirror-image alignment with the first shaft slot window 34) and whereinthe moveable jack member 22 resides between the first lateral sidewall44 and the second lateral sidewall 44, such that said shaft 64 extendsfrom the first shaft slot window 34 in the first lateral sidewall 44through said moveable jack member 22 and into the second shaft slotwindow in the second lateral sidewall 44.

Referring back now to FIG. 5, the shaft hole 32, in some embodiments, is½ inch diameter hole has drilled near the distal end of the vehicle jack18 in order to mount the jack foot 30. The pilot hole 52 may be used tomeasure and drill the shaft hole 32 in a round tube or a square tube atthe distal end of the vehicle jack 18.

In order to assist an installer in locating and drilling the shaft hole32 in the right location, the pilot hole 52 may be a 3/16 inch hole on alateral side 44 of the jack foot 30. In one embodiment, the pilot hole52 is located down from the support plate half the distance of an innerwidth of the jack foot 30. This way the pilot hole 52 is located atapproximately the center of an inner tube 22 of a vehicle jack 18.

The jack foot 30, in one embodiment, has an inner width that correspondsto a width of the inner tube 22 of the vehicle jack 18. In someembodiments, the jack foot 30 is available in different widths, in orderto accommodate vehicle jacks with different diameter tubing. The pilothole 52 may be located in a downward direction from the resting plate 46by half the inner width of the jack foot 30. By positioning the pilothole 52 in this manner, the pilot hole 52 is positioned correctly nearthe center of the appropriate diameter tube.

The pilot hole 52 also allows the shaft hole 32 to be positionedvertically at a specific position. In one embodiment, the pilot hole 52is positioned one and one half inches from the front surface 42 of thejack foot 30, and thus positions the shaft hole 32 one and one halfinches up from the bottom of the inner tube 22. Proper position of theshaft hole 32 may allow proper interaction of the cam surface 56 withthe striker plate 36 and allow the distal end of the inner tube 22 torest on the resting plate 46 when the jack foot 30 is being used.

In one embodiment, a striker plate 36 is placed between the jack foot 30and the proximal end of the vehicle jack 18. In other embodiments, (e.g.square shaped inner tubes 22), a striker plate 36 may not be needed ormay be an existing portion of the vehicle jack 18, trailer hitch 16,trailer tongue 14, trailer 10, fifth wheel trailer 94, RV 96, or othervehicle. In other words, the striker plate 36 may be an existing portionof the vehicle jack 18, trailer hitch 16, trailer tongue 14, trailer 10,fifth wheel trailer 94, RV 96, or other vehicle.

In one embodiment, the striker plate 36 is free floating and can moveabout the inner tube 22 for ease of manufacture and installation.However, the striker plate 36 can also be attached to the outer tube(not shown) or other stationary body via welding, adhesives, molding, bytabs on the striker plate 36 allowing it to be mounted (e.g. screwed) tothe outer tube or stationary body, or by any other means of attachmentwell known to those skilled in the art.

The striker plate 36, in some embodiments, is shaped like a circularO-ring or washer. However, the striker plate 36 can also besquare-shaped or any other suitable shape and still operate for purposesof the present disclosure. The striker plate 36 can be made of variousmaterials, including, but not limited to: steel, nylon, plastic,polyurethane, etc. and/or combinations thereof. The striker plate 36 mayhave an inner diameter (or shape) that is larger than the inner tube 22and smaller than the outer tube. Furthermore, the striker plate 36 mayhave an outer diameter (or shape) that is sufficiently large to providesubstantial contact with the top of the jack foot 30. Details of theoperation of the striker plate 36 will be discussed in further detailbelow.

In some embodiments, the jack foot 30 may also have a U-shapedstabilizer 38 shaped to conform to the shape of the inner tube 22 tohelp stabilize the inner tube 22 within the jack foot 30 when the jackfoot 30 is in the extended position. However, the stabilizer 38 can alsoassume other shapes to interact with the inner tube 22 to help stabilizethe inner tube 22 within the jack foot 30 when the jack foot 30 is inthe extended position. The stabilizer 38 can also help lock the jackfoot 30 in the extended position and keep it from collapsing if thevehicle rolls forward or backwards. Furthermore, the interior channel(not shown) of the jack foot 30 can also assume a U-shape or any othershape to interact with the inner tube 22 so as to stabilize the innertube 22 within the jack foot 30 when the jack foot 30 is in the extendedposition. For example, the interior channel of the jack foot 30 can beshaped to work with round or square jack inner tubes 22.

The interior channel of the jack foot 30 can also have a resting plate46 to contact, support, and stabilize the inner tube 22 in the extendedposition and, in some embodiments, bear all or substantially all of theload of the vehicle transmitted to the resting plate 46 through theinner tube 22. However, in other embodiments, the load of the vehicletransmitted through the inner tube 22 may be borne by the jack foot 30through the shaft (not shown) bearing on the bottom surface of the shaftslot window 34.

Additionally, the jack foot 30 can also have a base 54 to help stabilizethe vehicle jack 18 and the vehicle. In one embodiment, the front andback sides of base 54 are bent or curved upward to help facilitate theretracting and extending motion of the jack foot 30, as will bediscussed in further detail below.

Continuing with FIG. 5, The top of the front side 42 of the jack foot 30can also have an inner tube window 40 cut into, or otherwise formed in,the front side 42 of the jack foot 30 for receiving the distal end ofinner tube 22 in the retracted position to allow the jack foot 30 torotate without catching or jamming on the end of inner tube 22(discussed in more detail below). The jack foot 30 may also haveretaining pin holes 48 to help hold the jack foot 30 in the retractedposition by inserting a retaining pin (not shown) through the retainingpin holes 48. The retaining pin holes can be located above or below theshaft slot window 34.

The jack foot 30 may also have cut out slot 50 designed for minimalinterference with trailer tongues in the retracted position. The jackfoot 30 may also have a curved cam surface 56 to help facilitate theretracting and extending motion of jack foot 30.

The jack foot 30, in some embodiments, has a proximal end 74. In oneembodiment, the proximal end 74 is a portion of the jack foot 30 thatfirst contacts the striker plate 36 as the vehicle jack 18 is moved froma lowered to a raised position when the jack foot 30 is in an extendedposition. In certain embodiments, the jack foot 30 has a back side 66.In one embodiment, the back side 66 is a portion of the jack foot 30that contacts the striker plate 36 when the vehicle jack 18 is in afully raised position.

The jack foot 30 may be constructed using any material capable ofperforming the described functions of the jack foot 30 and also capableof supporting the tongue weight of a trailer 10 or the weight of aportion of another type of vehicle. For example, the jack foot 30 may beconstructed using steel, aluminum, a composite material, an alloy, acombination of the above-listed materials, or another material.

FIG. 6 shows a view of the front side 42 of the jack foot 30 shown inFIG. 5 and unattached to the inner tube 22 of the vehicle jack 18. FIG.6 shows a front side view of base 54 and inner tube window 40.

FIG. 7 illustrates a view of the back side 42 of the jack foot 30 shownin FIG. 5 and unattached to the inner tube of the jack. FIG. 7 alsoshows a back side view of the base 54, the inner tube window 40, and theresting plate 46. In one embodiment, the back side of the jack foot 30is at least partially open forming an interior channel 72 for receivingthe inner tube 22. In some embodiments, the back side 66 of the jackfoot 30 is enclosed by a surface of the jack foot 30 below the restingplate 46.

In certain embodiments, the resting plate 46 is positioned on the jackfoot 30 such that a top surface of the resting plate 46 is apre-determined extension length 90 from a bottom of the base 54. Theextension length 90 is the amount of extension provided by the jack foot30 when the jack foot 30 is extended and loaded. In other words, thejack foot 30, installed and in use with the vehicle jack 18, extends theeffective height of the vehicle jack by the extension length 90. Theextension length 90 may be any length by which the effective height ofthe vehicle jack 18 is to be extended. For example, the extension length90 may be a length between three and nine inches. In some embodiments,the jack foot 30 may be available in varying extension lengths 90, suchas a four inch extension length 90, a six inch extension length 90, andan eight inch extension length 90. The extension length 90, in someembodiments, is adjustable. For example, the resting plate 46 may beremovable and attachable on the jack foot 30 at varying positions.

FIGS. 8-12 illustrate the retracting and extending motions of the jackfoot 30 in accordance with the present disclosure. The jack foot 30, inone embodiment, is designed to automatically rotate upward as the innertube 22 of the vehicle jack 18 is retracted up into the outer tube 20.As will be seen, the automatic retraction or rotation of the jack foot30 can be obtained by the specific design and interaction between thecam surface 56, the striker plate 36 and the location of the top of theshaft slot window 34. However, it is to be understood that manualrotation may also be used without departing from the spirit or scope ofthis disclosure. For example, the operator can manually rotate the jackfoot 30 and use a retaining pin (not shown) and retaining pin holes 48to lock the jack foot 30 in a retracted position.

FIG. 8 shows the first stages of jack foot 30 retraction with the innertube 22 rising such that a shaft 64 also rises and travels the path ofshaft slot window 34, indicated by arrow 58, until the shaft 64 reachesthe proximal end of the shaft slot window 34. The shaft 64 travels thepath 58 of the shaft slot window 34 in response to the jack foot 30becoming unloaded. As load is removed from the jack foot 30 in responseto the vehicle jack 18 being retracted, the weight of the jack foot 30causes the jack foot 30 to remain resting on the ground as the vehiclejack 18 is retracted the vertical length of the shaft slot window 34.Under the influence of gravity, the shaft 64 travels from the distal endof the shaft slot window 34 to the proximal end of the shaft slot window34 during an initial phase of retraction of the vehicle jack 18.

FIG. 8 a shows one embodiment of the jack foot 30 and illustratesaspects of the jack foot 30 relating to physical properties of the jackfoot 30. The jack foot 30 includes a center of mass 76, a geometriccenter 78 of the lateral side 44, and a vertical mass axis 80.

The center of mass 76 of the jack foot 30 is a point defined by theaverage location of all of the mass of the jack foot 30. In someembodiments, the center of mass 76, as viewed from a lateral side (asshown in FIG. 8 a) is located closer to the front side 42 of the jackfoot 30 than the back side 66 of the jack foot 30. In some embodiments,the center of mass 76, as viewed from a lateral side (as shown in FIG. 8a) is located closer to the front side 42 of the jack foot 30 than isthe geometric center 78 of the lateral side 44 of the jack foot 30.

The geometric center 78 of the lateral side 44 is a point defined by theaverage position of all of the points of the lateral side 44. Thegeometric center 78 is, in essence, the middle point of the lateralsurface 44. In some embodiments, the geometric center 78 is roughlyequidistant from the front side 42 and the back side 66 of the jack foot30.

In one embodiment, the vertical mass axis 80 is an imaginary line drawnthrough the center of mass 76 and extending in a vertical direction whenthe jack foot 30 is in a lowered position, as illustrated in FIG. 8 a.Notably, if the jack foot 30 is supported at a point above the center ofmass 76 and on the vertical mass axis 80, the jack foot 30 will tend toorient itself in the lowered position as illustrated in FIG. 8 a.

As illustrated in FIG. 8 a, the shaft 64 may move to a proximal end ofthe shaft slot window 34 as the vehicle jack 18 is retracted. In someembodiments, the proximal end of the shaft slot window 34 is locatedbetween the vertical mass axis 80 and the back side 66 of the jack foot30. In response to the vehicle jack 18 being retracted to a point thatthe jack foot 30 is no longer supported by the ground and is supportedby the shaft 64, the jack foot 30 may rotate so that the center of mass76 is located directly below the shaft 64. This initial rotation of thejack foot 30 may help facilitate subsequent rotation of the jack foot 30by the cam surface 56 and the striker plate 36.

FIG. 8 b illustrates one embodiment of the jack foot 30 and showsgeometric properties of the jack foot 30. The jack foot includes acenter of mass 76, a geometric center 78 of the lateral side 44, and avertical center axis 82. The center of mass 76 and the geometric center78 of the lateral side 44 are substantially similar to same-numberedcomponents described in relation to FIG. 8 a.

The vertical center axis 82, in one embodiment, is an imaginary linedrawn through the geometric center 78 of the lateral side 44 andextending in a vertical direction when the jack foot 30 is in a loweredposition, as illustrated in FIG. 8 b. In some embodiments, the verticalcenter axis 82 is located nearer or more distant from the front sidethan is the vertical mass axis 80 when viewed from the lateral side 44.In one embodiment, the vertical center axis 82 is located the samedistance from the front side 42 as is the vertical mass axis 80 whenviewed from the lateral side 44.

FIG. 8 c illustrates one embodiment of a jack foot 30 showing the camsurface 56. The jack foot 30 includes a proximal end 74, a cam surface56, a back surface 66, and a shaft 64 having shaft axis 84, which mayalso be referred to as a rotation axis 84. The proximal end 74, camsurface 56, back surface 66, and shaft axis 84 are substantially similarto same-numbered components described in relation to FIG. 5.

The cam surface 56, in one embodiment, is a curved surface thatinteracts with the striker plate 36 to cause the jack foot 30 to rotatefrom a lowered position to a raised position in response to the vehiclejack 18 moving from an extended position to a retracted position, andthe striker plate 36 may therefore be referred to as jack footmotion-path-altering member. In one embodiment, the cam surface 56 runsfrom the proximal end 74 of the jack foot 30 to the back surface 66 ofthe jack foot. The proximal end 74, the cam surface 56, and the backsurface 66 may be described as an edge of the jack foot 30.

In some embodiments, the jack foot 30 rotates around a rotation axis 84as it moves from a lowered position to a raised position. The rotationaxis 84, in one embodiment, is positioned at the center of the shaft 64when the shaft is located at the proximal end of the shaft slot window34, as depicted in FIG. 8 c. The rotation axis 84, in some embodiments,is substantially perpendicular to a long axis 86 of the vehicle jack 18.The long axis 86 of the vehicle jack 18 may be defined as an axisrunning along the inner tube 22 of the vehicle jack 18. As depicted inFIG. 8 c, the rotation axis 84 extends substantially into and out of thepage.

The cam surface 56, in one embodiment, terminates at a radius 88 fromthe rotation axis 84 of the jack foot 30. The cam surface 56 may includea curve defining multiple radii 88 extending between the rotation axis84 and the cam surface 56 or edge of the jack foot 30. The radii 88 mayvary over the cam surface 56. In certain embodiments, the radii 88decrease as the cam surface 56 runs from the proximal end 74 to the backsurface 66. The decreasing radii 88 of the cam surface 56 interact withthe striker plate 36 to cause the jack foot 30 to rotate to a raisedposition as the vehicle jack 18 is retracted, and to rotate to a loweredposition as the vehicle jack 18 is extended.

The radius 88 may decrease at a constant rate as the cam surface 56 runsfrom the proximal end 74 to the back surface 66. For example, the radius88 may decrease by a constant amount per degree of rotation of the jackfoot 30. In some embodiments, the radius 88 decreases at a constant rateover a portion of the cam surface 56. The radius 88 of the cam surface56, in some embodiments, decreases at a varying rate over a portion orall of the cam surface 56.

FIG. 8 d is a side view of one jack foot 30 embodiment illustrating thecam surface 56. The jack foot 30 includes a rotation axis 84 and avarying cam radius 88. The varying radius 88 decreases as the camsurface 56 runs from the proximal end 74 to the back side 66. Forillustrative purposes, the radius 88 may be measured at varying anglesfrom an imaginary angle measurement line drawn through the rotation axis84 and running horizontally when the jack foot 30 is in the extendedposition. In one embodiment, the radius 88 is approximately 1.289 inchesat 90 degrees from the angle measurement line, approximately 1.066inches at 70 degrees from the angle measurement line, approximately0.868 inches at 30 degrees from the angle measurement line,approximately 0.719 inches at 30 degrees from the angle measurementline, and approximately 0.625 inches at 0 degrees from the anglemeasurement line.

Referring now to FIG. 9, as the inner tube 22 continues to rise, thejack can be lifted off the ground and begin to rotate counterclockwisein the direction of arrow 60, due to gravity as described above inrelation to FIG. 8 a. With increasing retraction of the inner tube 22,the jack foot 30 continues to rise until the striker plate 36 (if used)comes into contact with a rigid body (such as the trailer tongue 62 orouter tube 20 of the vehicle jack 18, if the striker plate 36 isfree-floating), and the top of the cam surface 56 comes into contactwith the striker plate 36. A striker plate 36 that is positioned in amanner that causes the cam surface 56 to contact the striker plate 36 asthe vehicle jack 18 is retracted can be said to be “aligned” with thecam surface 56. The cam surface 56 is positioned on the jack foot 30such that it is adapted to interact with the striker plate 36. Theinteraction between the cam surface 56 and the striker plate 36 maycause the jack foot 30 to rotate in response to movement of the vehiclejack 18 from a lowered position to a raised position.

At this point, the shaft 64 is positioned lower and to the rear of thepoint of contact between the top of the cam surface 56 and the strikerplate 36, such that the shaft 64 is closer to the back surface 66 ofjack foot 30. As the inner tube 22 continues to rise, the shaft 64 inthe slot 34 continues to rise and the jack foot 30 retracts further androtates such that the distal end of the jack foot 30 moves backwards andupward, as illustrated by the direction of arrow 60, due to shape of thecam surface 56 in relation to the position of the shaft 64 and the slot34. This backward and upward rotation continues until the jack foot 30is fully retracted, preferably in a substantially horizontal position(see FIG. 10), or the jack foot 30 is retracted far enough to not impedetransportation or movement of the trailer 10, fifth wheel trailer 94, RV96, or other vehicle. It will be appreciated that while the descriptionabove refers to the jack foot 30 rotating upward and backward, the jackfoot 30 may be designed to move an any direction that creates additionalclearance between the jack foot 30 and the ground. For example, the jackfoot 30 may be configured to rotate upward and frontward or upward andto a lateral side as the vehicle jack 18 is retracted.

FIGS. 10-12 illustrate the extension of jack foot 30 from the retractedposition to the fully extended position. FIG. 10 shows the jack foot 30fully retracted. As the inner tube 22 is extended, the jack foot 30rotates in a downward and frontward direction as indicated by arrow 68due to gravity overcoming the reduced frictional forces imposed by shaft64 on cam surface 56 which is in contact with striker plate 36.

The curvature of cam surface 56 can be any size and shape and can varyover the entire surface of the cam 56. The curvature of cam surface 56can be such that it forms part of a circle, osculating circle,ellipsoid, oblate ellipsoid or other curved shape, including non-curvedshaped composed of straight or substantially straight lines. In oneembodiment, the cam surface 56 is smooth and curved to minimizefrictional forces between the striker plate 36 and the cam surface 56during retraction and extension. In a one embodiment, the distancebetween the shaft 64 and the cam surface 56 decreases moving from thetop of the cam surface 56 (closer to the front surface 42 of jack foot30) to the bottom of the cam surface 56 on the back side 66 of jack foot30 to help impart a rotational force on jack foot 30.

With reference to FIG. 12, the jack foot 30, in one embodiment, isdesigned to automatically lock into an extended position as the innertube 22 of the vehicle jack 18 is further extended. The automaticlocking of jack foot 30 into the extended position can be obtained bythe specific design and interaction between the shape of the shaft slotwindow 34, the position of shaft 64, the shape of the interior channel72 of the jack foot 30 and the position of the resting plate 46 insideof the interior channel 72.

As the vehicle jack 18 is extended, the jack foot 30 rotates clockwiseand contacts the ground. As the load on the vehicle jack 18 increases,the shaft 64 follows the path of the shaft slot window 34 downward untilit substantially reaches the distal end of shaft slot window 34. Thejack foot 30 with the shaft 64 positioned at the distal end of the shaftslot window 34 is said to be “loaded,” while the jack foot with theshaft 64 positioned at the proximal end of the shaft slot window 34 issaid to be “unloaded.” Additionally, the jack foot 30 may slightly moverearward due to the force imposed upon the edges of slot 34 by shaft 64,until the jack foot 30 reaches the fully extended position. In the fullyextended position, the distal end of the inner tube 22 may contact theresting plate 46 and bear all or substantially all of the trailer tongueweight and, at the same time, one or more sides of the inner tube 22 maycontact one or more sides of the inner channel 72 (and/or u-shapedstabilizer 38) of the jack foot 30 to help stabilize the inner tube 22within the jack foot 30. In this manner, the size, shape, and positionof the shaft slot window 34 allows the jack foot 30 to lock into placein the up or down position.

In some embodiments, the shaft slot window 34 is also designed to lockthe jack foot 30 from collapsing if the trailer rolls forward.Additionally, the shape of the shaft slot window 34 can vary, but thestarting and ending points of the shaft slot window 34 may be the sameor substantially similar. For example, the shape of the shaft slotwindow 34 can be dog-legged, v-shaped, u-shaped, L-shaped, Z-shaped,C-shaped or any other suitable shape.

Those having ordinary skill in the relevant art will appreciate theadvantages provided by the features of the present disclosure. Forexample, it is a feature of the present disclosure to provide a jackassist device which is simple in design and manufacture. Another featureof the present disclosure is to provide a jack assist device capable ofreducing the time and effort required to operate the jack to hitch andunhitch a trailer. It is a further feature of the present disclosure, inaccordance with one aspect thereof, to provide a jack assist devicewhich is retractable and portable which eliminates the need of stowingseparate spacers or blocking, (e.g. blocks of wood, cinder blocks,etc.).

In the foregoing Detailed Description, various features of the presentdisclosure are grouped together in a single embodiment for the purposeof streamlining the disclosure. This method of disclosure is not to beinterpreted as reflecting an intention that the claimed disclosurerequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment.

It is to be understood that the above-described arrangements are onlyillustrative of the application of the principles of the presentdisclosure. Numerous modifications and alternative arrangements may bedevised by those skilled in the art without departing from the spiritand scope of the present disclosure. Thus, while the present disclosurehas been shown in the drawings and described above with particularityand detail, it will be apparent to those of ordinary skill in the artthat numerous modifications, including, but not limited to, variationsin size, materials, shape, form, function and manner of operation,assembly and use may be made without departing from the principles andconcepts set forth herein.

What is claimed is:
 1. A system for supporting a vehicle comprising: avehicle jack in mechanical communication with a jack foot and a strikerplate; wherein the jack foot is rotatable relative to the vehicle jackon a rotation axis disposed on the vehicle jack; wherein the jack footcomprises: a base disposed at a distal end of the jack foot, and a camsurface disposed at least in part at a proximal end of the jack foot,wherein the cam surface is positioned such that it is adapted tointeract with the striker plate to rotate the jack foot in response tomovement of the vehicle jack from a lowered position to a raisedposition; a shaft connecting the jack foot to the vehicle jack; a shaftslot window disposed on the jack foot; wherein the shaft is slidablyconnected to the shaft slot window; wherein the shaft slot windowcomprises a non-linear shape.
 2. The system of claim 1, wherein the camsurface comprises an edge of the jack foot from the proximal end of thejack foot to a back surface of the jack foot.
 3. The system of claim 2,wherein the edge of the jack foot comprises a curve defining a pluralityof radii extending between the rotation axis and the edge of the jackfoot, such that the radii decrease in length from the proximal end ofthe jack foot to the back surface of the jack foot.
 4. The system ofclaim 3, wherein the radius from the rotation axis decreases from theproximal end of the jack foot to the back surface of the jack foot at aconstant rate.
 5. The system of claim 3, wherein the radius from therotation axis decreases from the proximal end of the jack foot to theback surface of the jack foot from approximately 1.3 inches near theproximal end of the jack foot to approximately 0.6 inches near the backside of the jack foot.
 6. The system of claim 1, wherein the shaftcomprises a bolt.
 7. The system of claim 1, wherein the shaft isdisposed at the rotation axis.
 8. The system of claim 1, wherein: theshaft is disposed at a proximal end of the shaft slot window in responseto the jack foot being unloaded; and the shaft is disposed at a distalend of the shaft slot window in response to the jack foot being loaded.9. A system for supporting a vehicle comprising: a vehicle jack inmechanical communication with a jack foot and a striker plate; whereinthe jack foot is rotatable relative to the vehicle jack on a rotationaxis disposed on the vehicle jack; wherein the jack foot comprises abase disposed at a distal end of the jack foot and a cam surfacedisposed at least in part at a proximal end of the jack foot; whereinthe cam surface is positioned such that it is adapted to interact withthe striker plate to rotate the jack foot in response to movement of thevehicle jack from a lowered position to a raised position; a shaftconnecting the jack foot to the vehicle jack; a slot window disposed onthe jack foot; wherein the shaft is slidably connected to the shaft slotwindow; wherein the shaft is disposed at a proximal end of the shaftslot window in response to the jack foot being unloaded; wherein theshaft is disposed at a distal end of the shaft slot window in responseto the jack foot being loaded; and wherein the shaft slot windowcomprises a shape selected from the group consisting of a dog-leg, av-shape, a u-shape, an L-shape, a Z-shape, and a C-shape.
 10. A systemfor supporting a vehicle comprising: a vehicle jack in mechanicalcommunication with a jack foot and a striker plate; wherein the jackfoot is rotatable relative to the vehicle jack on a rotation axisdisposed on the vehicle jack; wherein the jack foot comprises a basedisposed at a distal end of the jack foot and a cam surface disposed atleast in part at a proximal end of the jack foot; wherein the camsurface is positioned such that it is adapted to interact with thestriker plate to rotate the jack foot in response to movement of thevehicle jack from a lowered position to a raised position; a shaftconnecting the jack foot to the vehicle jack; a slot window disposed onthe jack foot; wherein the shaft is slidably connected to the shaft slotwindow; wherein the shaft is disposed at a proximal end of the shaftslot window in response to the jack foot being unloaded; wherein theshaft is disposed at a distal end of the shaft slot window in responseto the jack foot being loaded; and wherein the proximal end of the shaftslot window is nearer to a back surface of the jack foot than is thedistal end of the shaft slot window.
 11. A system for supporting avehicle comprising: a vehicle jack in mechanical communication with ajack foot and a striker plate; wherein the jack foot is rotatablerelative to the vehicle jack on a rotation axis disposed on the vehiclejack; wherein the jack foot comprises a base disposed at a distal end ofthe jack foot and a cam surface disposed at least in part at a proximalend of the jack foot; wherein the cam surface is positioned such that itis adapted to interact with the striker plate to rotate the jack foot inresponse to movement of the vehicle jack from a lowered position to araised position; a shaft connecting the jack foot to the vehicle jack; aslot window disposed on the jack foot; wherein the shaft is slidablyconnected to the shaft slot window; wherein the shaft is disposed at aproximal end of the shaft slot window in response to the jack foot beingunloaded; wherein the shaft is disposed at a distal end of the shaftslot window in response to the jack foot being loaded; and wherein theproximal end of the shaft slot window is disposed between a back surfaceof the jack foot and vertical center axis drawn through a geometriccenter of a lateral side and parallel to a long axis of the jack foot.12. A system for supporting a vehicle comprising: a vehicle jack inmechanical communication with a jack foot and a striker plate; whereinthe jack foot is rotatable relative to the vehicle jack on a rotationaxis disposed on the vehicle jack; wherein the jack foot comprises abase disposed at a distal end of the jack foot and a cam surfacedisposed at least in part at a proximal end of the jack foot; whereinthe cam surface is positioned such that it is adapted to interact withthe striker plate to rotate the jack foot in response to movement of thevehicle jack from a lowered position to a raised position; a shaftconnecting the jack foot to the vehicle jack; a slot window disposed onthe jack foot; wherein the shaft is slidably connected to the shaft slotwindow; wherein the shaft is disposed at a proximal end of the shaftslot window in response to the jack foot being unloaded; wherein theshaft is disposed at a distal end of the shaft slot window in responseto the jack foot being loaded; and wherein the proximal end of the shaftslot window is disposed between a back surface of the jack foot andvertical mass axis drawn through a center of mass of the jack foot andparallel to a long axis of the jack foot.
 13. A system for supporting avehicle comprising: a vehicle jack in mechanical communication with ajack foot and a striker plate; wherein the jack foot is rotatablerelative to the vehicle jack on a rotation axis disposed on the vehiclejack; wherein the jack foot comprises a base disposed at a distal end ofthe jack foot and a cam surface disposed at least in part at a proximalend of the jack foot; wherein the cam surface is positioned such that itis adapted to interact with the striker plate to rotate the jack foot inresponse to movement of the vehicle jack from a lowered position to araised position; wherein a distance between the base plate and a distalend of a shaft slot window is between three and nine inches.
 14. Thesystem of claim 1, wherein the striker plate is slidably connected tothe vehicle jack.
 15. The system of claim 1, wherein the striker plateis fixed relative to the vehicle jack.
 16. A system for supporting avehicle comprising: a vehicle jack in mechanical communication with ajack foot and a striker plate; wherein the jack foot is rotatablerelative to the vehicle jack on a rotation axis disposed on the vehiclejack; wherein the jack foot comprises a base disposed at a distal end ofthe jack foot and a cam surface disposed at least in part at a proximalend of the jack foot; wherein the cam surface is positioned such that itis adapted to interact with the striker plate to rotate the jack foot inresponse to movement of the vehicle jack from a lowered position to araised position; wherein the jack foot further comprises a pilot holedisposed on a lateral side of the jack foot, and wherein the pilot holeis located a pre-determined distance from a front side of the jack foot,the pre-determined distance defined by a preferred location for drillinga hole in the vehicle jack to receive a shaft for connecting the jackfoot to the vehicle jack.
 17. The system of claim 1, further comprisinga retaining pin hole disposed on a lateral side of the jack foot toreceive a retaining pin holding the jack foot in the raised position.18. The system of claim 1, wherein the jack foot further comprises aresting plate disposed between two lateral surfaces of the jack foot,wherein the resting plate includes a top surface perpendicular to thelong axis of the vehicle jack when the jack foot is in a loweredposition, and wherein the vehicle jack contacts the top surface of theresting plate when the jack foot is loaded.
 19. The system of claim 1,wherein the jack foot further comprises a stabilizer disposed at theproximal end of the jack foot, the stabilizer to contact the vehiclejack when the jack foot is in a lowered position.
 20. The system ofclaim 1, wherein the jack foot further comprises an inner tube windowdefined by an aperture in a front surface of the jack foot, the innertube window to provide clearance between the vehicle jack and the jackfoot when the jack foot is in the raised position.
 21. The system ofclaim 1, wherein the vehicle jack is selected from the group consistingof a trailer tongue jack and a corner jack.
 22. The system of claim 1,wherein the vehicle jack is selected from the group consisting of ascrew jack, an electrically-actuated screw jack, and a hydraulic jack.23. The system of claim 1, wherein the rotation axis is perpendicular toa long axis of the vehicle jack.
 24. A jack foot attachable to a vehiclejack for supporting a trailer tongue comprising: a base disposed at adistal end of the jack foot; a cam surface disposed at least in part ata proximal end of the jack foot; wherein the cam surface is positionedsuch that it is adapted to interact with a striker plate to rotate thejack foot around a rotation axis in response to movement of the jackfoot from a lowered position to a raised position; wherein the edge ofthe jack foot comprises a curve defining a plurality of radii extendingbetween the rotation axis and the edge of the jack foot, such that theradii decrease in length from the proximal end of the jack foot to theback surface of the jack foot.
 25. The jack foot of claim 24, whereinthe cam surface comprises an edge of the jack foot from the proximal endof the jack foot to a back surface of the jack foot.
 26. The jack footof claim 24, wherein the radius from the rotation axis decreases fromthe proximal end of the jack foot to the back surface of the jack footat a constant rate.
 27. The jack foot of claim 24, wherein the radiusfrom the rotation axis decreases from the proximal end of the jack footto the back surface of the jack foot from approximately 1.3 inches nearthe proximal end of the jack foot to approximately 0.6 inches near theback side of the jack foot.
 28. The jack foot of claim 24, furthercomprising a shaft to connect the jack foot to a vehicle jack.
 29. Thejack foot of claim 28, wherein the shaft comprises a bolt.
 30. The jackfoot of claim 28, wherein the shaft is disposed at the rotation axis.31. The jack foot of claim 28, further comprising a shaft slot windowdisposed on the jack foot, wherein: the shaft is slidably connected tothe shaft slot window; the shaft is disposed at a proximal end of theshaft slot window in response to the jack foot being unloaded; and theshaft is disposed at a distal end of the shaft slot window in responseto the jack foot being loaded.
 32. The jack foot of claim 31, whereinthe shaft slot window comprises a shape selected from the groupconsisting of a dog-leg, a v-shape, a u-shape, an L-shape, a Z-shape,and a C-shape.
 33. The jack foot of claim 31, wherein the proximal endof the shaft slot window is nearer to a back surface of the jack footthan is the distal end of the shaft slot window.
 34. The jack foot ofclaim 31, wherein the proximal end of the shaft slot window is disposedbetween a back surface of the jack foot and vertical center axis drawnthrough a geometric center of a lateral side and parallel to a long axisof the jack foot.
 35. The jack foot of claim 31, wherein the proximalend of the shaft slot window is disposed between a back surface of thejack foot and vertical mass axis drawn through a center of mass of thejack foot and parallel to a long axis of the jack foot.
 36. The jackfoot of claim 24, wherein a distance between the base plate and a distalend of a shaft slot window is between three and nine inches.
 37. Thejack foot of claim 24, wherein the striker plate is slidably connectableto the vehicle jack.
 38. The jack foot of claim 24, wherein the strikerplate is fixedly connectable relative to the vehicle jack.
 39. The jackfoot of claim 24, wherein the jack foot further comprises a pilot holedisposed on a lateral side of the jack foot, and wherein the pilot holeis located a pre-determined distance from a front side of the jack foot,the pre-determined distance defined by a preferred location for drillinga hole in a vehicle jack to receive a shaft for connecting the jack footto the vehicle jack.
 40. The jack foot of claim 24, further comprising aretaining pin hole disposed on a lateral side of the jack foot toreceive a retaining pin holding the jack foot in the raised position.41. The jack foot of claim 24, wherein the jack foot further comprises aresting plate disposed between two lateral surfaces of the jack foot,wherein the resting plate includes a top surface perpendicular to thelong axis of the jack foot when the jack foot is in a lowered position,and wherein a vehicle jack contacts the top surface of the resting platewhen the jack foot is loaded.
 42. The jack foot of claim 24, wherein thejack foot further comprises a stabilizer disposed at the proximal end ofthe jack foot, the stabilizer to contact a vehicle jack when the jackfoot is in a lowered position.
 43. The jack foot of claim 24, whereinthe jack foot further comprises an inner tube window defined by anaperture in a front surface of the jack foot, the inner tube window toprovide clearance between a vehicle jack and the jack foot when the jackfoot is in the raised position.
 44. The jack foot of claim 24, whereinthe vehicle jack is selected from the group consisting of a trailertongue jack and a corner jack.
 45. The jack foot of claim 24, whereinthe vehicle jack is selected from the group consisting of a screw jack,an electrically-actuated screw jack, and a hydraulic jack.
 46. The jackfoot of claim 24, wherein the rotation axis is disposed on a vehiclejack and perpendicular to a long axis of the vehicle jack.
 47. A jackfoot comprising: a base disposed at a distal end of the jack foot; a camsurface disposed at least in part at a proximal end of the jack foot,wherein the cam surface: is positioned such that it is adapted tointeract with a striker plate to rotate the jack foot around a rotationaxis in response to movement of the jack foot from a lowered position toa raised position; comprises an edge of the jack foot from the proximalend of the jack foot to a back surface of the jack foot; and comprises acurve defining a plurality of radii extending between the rotation axisand the edge of the jack foot, such that the radii decrease in lengthfrom the proximal end of the jack foot to the back surface of the jackfoot; wherein the radius decreases from approximately 1.3 inches toapproximately 0.6 inches; a bolt disposed at the rotation axis toconnect the jack foot to a vehicle jack; a shaft slot window disposed onthe jack foot, wherein: the bolt is slidably connected to the shaft slotwindow; the bolt is disposed at a proximal end of the shaft slot windowin response to the jack foot being unloaded; the bolt is disposed at adistal end of the shaft slot window in response to the jack foot beingloaded; the shaft slot window comprises a dog-leg shape; the proximalend of the shaft slot window is nearer to a back surface of the jackfoot than is the distal end of the shaft slot window; the proximal endof the shaft slot window is disposed between a back surface of the jackfoot and vertical center axis drawn through a geometric center of alateral side and parallel to a long axis of the jack foot; and theproximal end of the shaft slot window is disposed between a back surfaceof the jack foot and vertical mass axis drawn through a center of massof the jack foot and parallel to a long axis of the jack foot; a pilothole disposed on a lateral side of the jack foot, and wherein the pilothole is located a pre-determined distance from a front side of the jackfoot, the pre-determined distance defined by a preferred location fordrilling a hole in a vehicle jack to receive the bolt for connecting thejack foot to the vehicle jack; a resting plate disposed between twolateral surfaces of the jack foot, wherein the resting plate includes atop surface perpendicular to the long axis of the jack foot when thejack foot is in a lowered position, and wherein the vehicle jackcontacts the top surface of the resting plate when the jack foot isloaded; an inner tube window defined by an aperture in a front surfaceof the jack foot, the inner tube window to provide clearance between thevehicle jack and the jack foot when the jack foot is in the raisedposition; and a stabilizer disposed at the proximal end of the jackfoot, the stabilizer to contact the vehicle jack when the jack foot isin a lowered position; and wherein the striker plate is slidablyconnectable to the vehicle jack; and wherein a distance between the baseand the distal end of the shaft slot window is approximately six inches.48. A system for supporting a vehicle comprising: a vehicle jack inmechanical communication with a jack foot; wherein the jack foot isrotatable relative to the vehicle jack on a rotation axis disposed onthe vehicle jack; wherein the jack foot comprises: a base disposed at adistal end of the jack foot; a front sidewall, and two opposing lateralsidewalls comprising a first lateral sidewall and a second lateralsidewall, wherein the front sidewall resides between and intercouplesthe two opposing lateral sidewalls to thereby form a three-sided jackfoot body having a distal end connected to the base; a first shaft slotformed in the first lateral sidewall, wherein said first shaft slotcomprises a substantially straight proximal section terminating in aproximal end and a substantially straight distal section terminating ina distal end, wherein the proximal section and the distal sectionintersect and form an angle θ therebetween.
 49. The system of claim 48,wherein a second shaft slot is formed in the second lateral sidewall,wherein said second shaft slot comprises a substantially straightproximal section terminating in a proximal end and a substantiallystraight distal section terminating in a distal end, wherein theproximal section and the distal section intersect and form an angle θtherebetween, the system further comprising: a shaft disposed within andextending between the first shaft slot and the second shaft slot, andwherein the jack includes a moveable jack member residing between thefirst lateral sidewall and the second lateral sidewall, such that saidshaft extends from the first shaft slot in the first lateral sidewallthrough said moveable jack member and into the second shaft slot in thesecond lateral sidewall.
 50. The system of claim 48, wherein the angleis an obtuse angle.
 51. The system of claim 50, wherein the angle iswithin a range of 95 degrees to 175 degrees.
 52. The system of claim 51,wherein the angle is 135 degrees.
 53. The system of claim 48, whereinthe shaft slot resides in the upper proximal third of the jack footbody.
 54. A system for supporting a vehicle comprising: a vehicle jackin mechanical communication with a jack foot and a jack footmotion-path-altering member; wherein the jack foot is rotatable relativeto the vehicle jack on a rotation axis disposed on the vehicle jack;wherein the jack foot comprises: a base disposed at a distal end of thejack foot, and a cam surface, wherein the cam surface is positioned suchthat it is adapted to interact with the jack foot motion-path-alteringmember to rotate the jack foot in response to movement of the vehiclejack from a lowered position to a raised position; a shaft connectingthe jack foot to the vehicle jack; and a shaft slot window disposed onthe jack foot; wherein the shaft is slidably connected to the shaft slotwindow; wherein the shaft slot window comprises a non-linear shape. 55.A system for supporting a vehicle comprising: a vehicle jack inmechanical communication with a jack foot and a jack footmotion-path-altering member; wherein the jack foot is rotatable relativeto the vehicle jack on a rotation axis disposed on the vehicle jack;wherein the jack foot comprises: a three-sided jack foot body havingthree side walls and an open side, and a resting plate surrounded bysaid three side walls; a base disposed at a distal end of the jack foot,and a cam surface; wherein the cam surface is positioned such that it isadapted to interact with the jack foot motion-path-altering member torotate the jack foot in response to movement of the vehicle jack from alowered position to a raised position.
 56. The system of claim 55,further comprising a base disposed on a distal end of the jack footbody, wherein the base is wider in all directions than, and therebysurrounds a perimeter of, said distal end of the jack foot body.
 57. Asystem for supporting a vehicle comprising: a vehicle jack in mechanicalcommunication with a jack foot and a jack foot motion-path-alteringmember; wherein the jack foot is rotatable relative to the vehicle jackon a rotation axis disposed on the vehicle jack; wherein the jack footcomprises: a three-sided jack foot body having three side walls and anopen side, said three side walls including a front side, and a windowformed in said front side for receiving a portion of the vehicle jacktherethrough during operation os said vehicle jack; a base disposed at adistal end of the jack foot, and a cam surface, wherein the cam surfaceis positioned such that it is adapted to interact with the jack footmotion-path-altering member to rotate the jack foot in response tomovement of the vehicle jack from a lowered position to a raisedposition.